Usual scenarios: 1. You tried to unzip the archive with something like 7zip or jzip. Solution - Download and install WinRar version 5.+ (basically get the latest build) as most archives on this site (for newer systems though) uses WinRar 5.+'s RAR5 algorithm which most other unzip applications do not support just yet. 2. You use WinRar but older versions of it. Solution - same as above, get the latest build. 3. The download actually got corrupted in transit. Solution - download, install and use a download manager for downloading large files as they provide a better and secure means of downloading larger files, plus you can pause and resume your download on demand.